Engineer&#39;s square.



Patented Aug. I9, |902.

j w. CHESTEBMAN.

'ENGINEERS SQUARE.

(Application Bled Nov. 16, 1901.)

(No Model.)

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l Y W TH: Nunnls PErEI-IS co. PHoTouYHo.. WASHINGTON. n. c.y

UNITED STATES ATENT OFFICE.

WILLIAM CHESTERMAN, OF SHEFEIELD, ENGLAND.

NGINEERS SQUARE.

SPECIFICATION forming part of Letters Patent N o. 707,301, dated August 19, 1902. Application filed November 16, 1901. Serial No. 82,549. (No model.)

T0 all whom zit may concern:

Beit known that I, WILLIAM CHESTERMAN, a citizen of England, residing at Bow Works, Sheflield,in the county of York, England, have invented a certain new and useful-Improvement in Engineers Squares, (for which Ihave obtained a patent in Great Britain, dated May 14, 1901, No. 9,989,) of which the following is a specification.

My invention relates to the construction of an. engineers square in such a way that the stock and blade can be easily made true and parallehsided and can be readily taken apart for repair and put together again in true relative position, as I shall describe, referring to the accompanying drawings.

Figure 1 is a front view, and Fig. 2 is a section, showing part of the stock and of the blade at the right angle of an engineers square. Fig. 3 shows an 'eccentric washer.

The stock a is made with its sides c o straight and parallel and a shoulder d exactly at right angles to the sides o.4 The blade b is also made with its sides straight and parallel,

and it is secured to the stock by screws e, its

edge bearing accurately against the shoulder d of the stock. In order to' press the blade against this shoulder not only at first when it is new, but also afterward when afterI wear its edges may have been partly cut away to make them straight and true, I put under the head of each of the screws e a circular washer f, the screw-hole through which is eccentric.' Each washer is lodged in a recess of the blade b, and the metal of the blade which forms the bottom of the recess has through it a hole (indicated by the larger dotted circle in Fig. 1) concentric with the recess and so much larger lthan the screw, which is indicated by the smaller dotted circle e, as to permit the blade being moved toward the shoulder d when the eccentric' Washer is turned on the screw as on an axis, for which purpose it has two holes to receive a fork-Spanner. One of the screws c and its washer fbeing inserted in the blade d, the washer is turned, pressing the bladeb against the shoulder d, so that it stands at right angies tothe sides of the stock, after which the other washers and screws are inserted in the blade and the screws are screwed down to hold the blade firmly in position.

Instead of four screws, as shown, there may be two or another number.

-The advantages of my invention result from the use of the washers having the eccentric holes for the screws, since they afford a simple andeftective device for forcing the blade against the shoulder d.

Having thus described the nature of my said invention and the best means I know of carrying the same into practical eiect, I claim- An engineers square having a stock with a transverse shoulder, a blade having recesses and secured to the stock by screws, and eccentric Washers in said recesses beneath the screw -heads arranged to press the blade against the shoulder, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

A WILLIAM CHESTERMAN. Witnesses:

THOMAS RENSHAW, W. H. CHAPMAN. 

